TRex Power Up problems
 

Hi guys,

Just got a used TRex and everything seems to be fine, with the exception of going to FULL POWER. I have everything trimed, the gyro gain is set perfect, blades in line and balanced.

Here is what is being used.

JR 8103 Radio
Align BL25T ESC
New 11.1v 1300Ma battery
Align 420LF motor

I go to power up and when the heli is at half or less power all is fine. This will get me up to about eye level. When I go to give a little more power, it starts shaking (missing power) and then comes down. I have locked the heli to the floor to check the power and when I go above half throttle, the power just quits.

Is the ESC wrong, or what do you think?
Thanks

RE: TRex Power Up problems
 

Try different esc settings?

Mine is new v2 but had similar troubles.
Set high protection down to middle protection on battery protect and took guvnor off and everything is fine now.
Also maybe borrow another battery and try that.

RE: TRex Power Up problems
 

sounds like the esc is cutting out due to low voltage... what c rating is the battery?

RE: TRex Power Up problems
 

1300 mAh is not enough for a t-rex, especially if it's got a lower C discharge rating.

It's likely your pack is dropping voltage heavily under load. Look at a 2100+ mAh pack with at least a 15C Discharge.

RE: TRex Power Up problems
 

Just tried a Maxamps 11.1V 2100mah and the same thing happens. Anymore ideas. I am going to try and set the ESC without Govener, and low voltage cutoff set to low.

RE: TRex Power Up problems
 

If you have your throttle at 1/2 you should have almost no angle of attack, as you increase power right before it loses power do you hear lots of air flowing thru the blades.......angle of attack to high maybe?

On the 8103 you have a throttle high, check to see if it can go higher...

I think your 8103 has a throttle to blade ratio increase..... towards the end of the powerband try lowering the blade angle of attack.

the best set up is one where YOU have control over throttle to blade increase and all the other mixes.... Its a challange but thats where the fun is....


see if you can increase your esc speed thru your 8103.......
tail does sound like your gains are off. you can also try to set those thru your 8103..

I have a piccolo pro with seperates and exp same trouble....

Good Luck

Just my .02c

Joe

RE: TRex Power Up problems
 

I have a thunder power 1300 its around 20c..It will fly the rex, I use it when doing adjustments sometimes when I do not want to wait for my 2070 or 2100 to charge. I think the esc is cutting out..

RE: TRex Power Up problems
 

Definitely a battery problem. A TREX needs at least 2,000mAH, 20C.

RE: TRex Power Up problems
 

well the 420lf is only a 3200kv motor and it works off a 25amp esc so you don't need that much battery or c rating to run it. I'm thinking the battery is just old and isn't putting out the rated voltage anymore.

You can upgrade but don't overdo it either, a nice 15c or 18c 1300 to 1800mah battery will be fine with that motor esc combo. you don't want to fry the motor either.

if you do want more power and flight times you may want to upgrade your motor/esc to the 430X/35G. at that point you'll need the higher C rating and larger battery.